SOLID OXIDE FUEL CELL, FUEL CELL STACK SYSTEM, FUEL CELL MODULE, AND FUEL CELL SYSTEM

A solid oxide fuel cell (10), a fuel cell stack device (11), a fuel cell module (18) and a fuel cell apparatus (23) are disclosed. The solid oxide fuel cell (10) includes a power-generating element unit (9). The power-generating element unit (9) includes a fuel electrode layer (3), a solid electrolyte layer (4) on the fuel electrode layer (3) and an oxygen electrode layer (6) on the solid electrolyte layer (4). The solid electrolyte layer (4) includes through holes (14) at least one of which includes a sealant (15) therein.